Pressure-gage



ATENT OFFICE.

CHARLES BARTLETT BOSWORTII, OF EVERETT, ASSIGNOR TO THE CROSBY STEAM GAGE AND VALVE COMPANY, OF BOSTON, MASSACHUSETTS.

PRESSURE-GAGE.

SPECIFICATION formingpart of Letters Patent No. 485,404, dated November 1, 1892.

Application filed July 29, 1892- Serial No. 441,569- (No model.)

To aZZ whom it may concern.-

Be it known that I, CHARLES BARTLETT Bos- WORTH, a citizen of the United States, residing at Everett, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Pressure or Vacuum Gages; and I do declare the following to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon,which form a part of this specification.

This invention relates to an improvement in steam-gages; and it consists of a single spring, which operates the index-hand mech anism by means of a V-shaped lever, one part of which is attached to the Bourdon tube, While another part in a vertical line of this attachment is connected to a post by a slot, which permits the vertical movement of the tube, as well as its movement in are when under pressure.

This invention is an improvement of the Crosby gage as seen in Patent No. 145,726, dated December 23, 1873. Figure 7 of that patent shows a bell-crank lever attached to the case at it, having at its outer end, at b, a link loosely jointed to it at one end, while the other end of the link is jointed to the Bourdon tube.-- Any movement of the tube will cause the bell-crank lever to rotate at h. Now, turning to Fig. 6, there will be observed the application of a jointed link, one end of whichis attached to the Bourdon tube, while the other end is attached to the case at h. The apex of this link is connected by a straight link to the sector which operates the index-hand. If there should be substituted this linkage and sector in Fig. 7, there would be the jointed link of the patent. If now the V-link should be made solid at its apex b, then there would be what the patent speaks of as a solid V-link. This solid V- link is substantially the Bosworth linkage without the slot where it is connected to the post of the gage. The importance of this slot is that it permits a freedom of movement of the tube-spring without any serious efiort to adjust it. While there is onlya single continuous movement of the Bourdon tube under pressure, yet from two defined lines, which are vertical and horizontal, it departs materially-that is, it rises above the horizontal line and recedes from the vertical lineso that, in the language of the Crosby patent, this movement is called the upward or vertical, as well as the horizontal movement,and both of which, when the link is free to move, are transmitted to operate the index-hand. This cannot take place to the largest extent, except when the V-link is jointed at its apex, and will spread apart under the movement of the tube or when the solid link is so disposed to the arc of movement that it will move without binding and thus transfer the rise of the tube. This cannot be so well done with the solid link, except as above located, and to obviate this was the object of the slot in the Bosworth link.

In the annexed drawings, Fig. 1 is a face view of a gage with part of the dial broken away. Fig. 2 is aview of the operative parts.

Referring to the drawings, the letter A indicates an ordinary steam-gage having the dial a, the pointer a, the spring a the supporting-frame a and the post a all as usual. To the post a of the pointer a is secured the toothed wheel I), which is engaged by the sector B, pivoted at b to the frame a To the outer extension 12 of the sector B is secured by a slotted connection an extension C. To the outer end a of this extension C is pivoted one end of a link D, the other end of which is pivoted to the V-link E. This V-link consists of an arm e, to which the link D is connected, and a head e, which is substantially V-shaped, and may be solid or open. The

apex e of'this head is pivoted at c to the loose end 1 of the Bourdon tube F, the other end f of which is connected in the usual way to the steam or exhaust pipe G. The shorter arm H of the V-shaped head 6' has at its end it the open slot or notch h. Through this slot passes the pin k into the post h sup ported by the gage-case, the end It being loose on said pin. As the Bourdon tube flexes under the variations of pressure and the intervening mechanism turns the pointer, the

slotted connection at the pin k allows for a free movement, so that the most delicate and exact registration may be made, as the parts do not and cannot bind.

Having thus described my invention, what I claim is 1. In a steam-gage, the combination of the Bourdon tube and the pointer with intervening mechanism connecting the two, one part of such mechanism consisting of a V-shaped link connected at its apex to the Bourdon Bourdon tube and the pointer with intervening mechanism connecting the two, one part of such mechanism consisting of a link, one arm of which is connected to the free end of the Bourdontube and the other arm havinga slotted connection with the gage-case and by an arm is attached to the pointer, as set forth.

In testimony whereof I aifix my signature in presence of two witnesses.

CHARLES BARTLETT BOSWORTII.

Witnesses:

J. H. MILLETT, D. P. BAILEY. 

